package main

import "fmt"

func foo2(s []int) {
	s[0] = 100
}
func foo3(s []int) {
	s[1] = 200
	s = append(s, 4)
	s[0] = 100
}
func main() {
	var s = []int{1, 2, 3}
	// foo2(s)
	foo3(s)
	fmt.Println(s)
}
